1) Field of the Invention
The present invention relates generally to an input and output (I/O) device and an I/O system, and more particularly to an I/O device and an I/O system that adjusts a voltage swing range.
2) Description of the Related Art
I/O devices have been widely used in electronic equipment. In order to distinguish whether a bit has one of two values in electronic circuits, a voltage or current is typically set to have a smaller or larger value compared with a reference value. As a result, two phases are distinguished and driven to perform an I/O operation.
If a voltage or current is greatly differentiated from the reference value, a read/write margin is increased so that data that have two values may be easily distinguishable. However, increasing the read/write margin leads to an increase in driving power consumption. Further, it is difficult to secure the driving speed when the read/write margin is increased.